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Now in this particular video, what I want to do is to turn your attention to

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some task scheduling options that we have available to us.

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So right now we are using the Ansible Automation system, so we obviously know

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the automation is a quite good thing.

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And one of the benefits of automation is that while we cut out things such as

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human error,

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or at least we try to minimize the possibility of human error.

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Now even before we were using all of these cool automation tools such as Ans

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ible or Terraform or whatever it may be,

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there were actually options to automatically schedule tasks directly on your
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there were actually options to automatically schedule tasks directly on your

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Linux system.

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So say for example, you wanted to perform a really, really important task,

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but let's maybe say it was at an inconvenient time.

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So let's maybe say you wanted to create some type of tar archive, a backup of

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your files,

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but basically you didn't want to do it during the week.

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Let's maybe say you wanted to perform this task at 8pm in the evening, you know

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,

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sometime well after everyone had left the office.

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Well, it would be kind of annoying to have to drive back in at 8pm, log into
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Well, it would be kind of annoying to have to drive back in at 8pm, log into

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the system and then perform that backup.

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Not exactly a good idea.

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Similarly, let's maybe say you wanted to perform some type of task during

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office hours,

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but you really don't want to run the risk of forgetting to do this task.

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It's so important that it cannot be missed.

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Well, once again, the solution to that type of problem would be to schedule a

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task.

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So that it executes automatically without you having to deal with it manually.

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Basically, it takes you out of the equation, you don't have to be at the system
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at the time of the process.

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And it also doesn't require that you remember about the process just at the

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time it's supposed to happen.

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So there are different ways to do such a thing, we can do something like a cron

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job.

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This would be a very good solution if you wanted to continually perform some

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type of task.

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However, what if you just wanted to perform some task on a one-off basis?

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Maybe you want to run a script one time at one particular hour on one

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particular date and that is it.

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In this case, the solution that we could use would be the "at" commands.
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Pretty much, this allows us to schedule a particular task or run a particular

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command at a very specific time.

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Say for example, let's do an LS, we can see what I have right here.

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What I'm going to do is I'm going to schedule the creation of a text file and

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let's maybe say one minute time.

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If I just say date, we can see the time is five minutes past two in the

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afternoon.

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And also it is at now plus one minute.

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All I'm going to do is echo in, "test file" into a file called "test.txt".
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All I'm going to do is echo in, "test file" into a file called "test.txt".

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And then once I'm done, I can press Ctrl D. Now if I happen to do an LS, notice

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the file is not yet created.

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But if I just wait that minute, then it will be created.

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So let's just do a date to see the time right now, give it a few more seconds.

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Let's do a date again, now a minute has elapsed. If I do an LS, check it out

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right here.

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The file hasn't been created. It was created exactly one minute after we had

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scheduled it as per instructions.

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So if I cat the file right there, now this is obviously a very, very trivial
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So if I cat the file right there, now this is obviously a very, very trivial

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example.

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Like I say, maybe you want to perform some type of backup, some type of update,

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maybe some type of check of a configuration file.

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Having the ability to do this via the "at" utility is going to allow us to

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schedule this as a one time job.

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So whilst I have the ability to perform this type of automation on this

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particular system, this is only one machine.

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What if I want to perform this task across maybe 500 machines I'm managing?

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Well I don't want to log in one by one by one by one and do that.

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That's going to take a lot of time. Instead, what if we can use Ansible to
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That's going to take a lot of time. Instead, what if we can use Ansible to

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effectively automate the automation?

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So that means we can push out that "at" command with the actual time that you

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want to run.

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And we can push it to all of our devices concurrently using automation.

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So if I go to my browser, if I just search for the Ansible at module, we will

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see this particular link here.

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Let's click it. Now again, notice this is part of the Ansible POSIX collection.

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So it's not going to be part of your built-in. Therefore, we're going to have

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to ensure that we do have our Ansible POSIX collection installed.
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to ensure that we do have our Ansible POSIX collection installed.

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We can do this via this particular command, although if you have been following

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along from previous skills,

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this particular collection should already exist on the device, but nevertheless

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, let's just type it in.

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As we can see here, I already have it. So if we check this in NOPS, as we can

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see, we can use this module to schedule a command or run a script.

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And have that run once in the future, like I say once is the key here.

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If we scroll on down, we can see some of the available options.

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We have the command parameter. This is going to take a string.
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We have the command parameter. This is going to take a string.

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And pretty much, this is just going to be the command that you want to run in

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the future.

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In my case here, when I happen to create that file, I run the echo command and

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pipe it into a text file.

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If I wanted that particular command to be scheduled via at using Ansible, I

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would pass that command directly into the command parameter.

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Now this part here is also important. This is the count. Notice it takes an

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integer value.

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This is the amount of units in the future that you want to have elapsed before

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the command runs.

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Now the actual unit here depends on what you specify. Are you going to do in
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Now the actual unit here depends on what you specify. Are you going to do in

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minutes, hours, whatever it may be?

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That can actually be controlled via another parameter. So again, if I scroll on

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down, here we have the option to specify exactly what units we want.

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So do we want to schedule something a few minutes in the future?

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Or maybe hours, perhaps some days? Or maybe even weeks in the future, we have

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this ability to specify this directly via the unit parameter.

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Now one other parameter that I just want to show you is if we just scroll on up

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a little bit.

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Now notice we have this script file option. This is the option we could use if
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Now notice we have this script file option. This is the option we could use if

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we actually want to run a parameter.

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We actually want to run a particular script in the future, not just a regular

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command.

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So why don't we go and give this a shot then? So the first thing I'm going to

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do is I'm going to create a very simple bash script.

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It's going to perform a very simple task. Now like I say, this is not going to

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be the most real world example.

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It's just to highlight the utility here. And you can use your imagination to

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think about all the weird and wonderful things that you could potentially do

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with a different style script.

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So let's go and create one right here. I'll just say them and I'll just say my
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So let's go and create one right here. I'll just say them and I'll just say my

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bash.sh and I'm going to insert mode.

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And all I will do at the top here is I'm going to add in my shebang and then

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forward slash bin forward slash bash.

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If you recall from the RHCSA examination, this is how we start off a bash

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script.

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The bash script is going to be super, super simple. All we're going to do is to

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echo in the words.

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This is just a little test and I'm going to redirect that into a file called my

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example dot txt.
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Okay, so we have this little script currently at resides in this particular

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directory home and simple directory.

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And what I want to do is I want this script to be present on both of my managed

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devices.

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That is the blue box and the yellow box. So what am I going to do?

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Well, I'm going to use the copy module. So let me just begin here by saying

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them play one dot ymail.

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I'll go into insert mode, have my three hyphens at the top and give the play a

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name.

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I'll just say play one copy script to targets.

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Who do I want to target? I want to target the all group and I'm going to set
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Who do I want to target? I want to target the all group and I'm going to set

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gather facts to the value of false to speed things up a little bit.

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Now what I'm going to do here is to find my tasks. So the task here is going to

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be called copy script to my servers.

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Now what am I going to do right here? Well, I'm going to use the Ansible built

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in copy module.

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Recall we saw this in a previous skill and this is going to allow us to copy a

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particular file from the control mode here to the target destinations.

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Now I'm going to have to supply some particular parameters namely the source

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parameter.

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Basically where can I find the file on my control machine that I want to copy
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Basically where can I find the file on my control machine that I want to copy

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and all I'll do is specify the path so you can find that here and home Ansible.

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And let me just check the name of the file once again. It's called my bash.sh.

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And now I specify the destination where abouts I want to copy this on the

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target device.

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Now just because this is a little demo I'll just copy it into the temp

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directory.

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So I'll copy it into temp my bash.sh so this is where it's going to be found on

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the yellow box and the blue box.

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Now one thing to note here when I happen to copy this particular file on my
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Now one thing to note here when I happen to copy this particular file on my

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control node to the blue box and yellow box on my targets.

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I want to make sure that this script is going to be executable because after

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all that isn't either bash script and it's going to need those particular

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permissions.

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So I'm not just going to specify that I'm going to copy this particular file

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from here to here.

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I want to ensure that it has those permissions.

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Now if you check the documentation you will see the way we can do this is by

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using the mode parameter.

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All I'm going to do here is specify the mode is going to be 0 7 5 5.
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All I'm going to do here is specify the mode is going to be 0 7 5 5.

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That's just the optonation to ensure that the owner has redry executable access

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and the groups and others also have red and execute.

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So with that now done what I'm going to do here is just save this for now.

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So all I will do here is say Ansible Playbook play one dot y mail and to enter.

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And as we can see here we have now copied over her scripts to those target

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devices.

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So if I see the end of the temp directory and do an LS and I just grip SH.

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As we can see here we do have this script present now on this device.
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As we can see here we do have this script present now on this device.

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So I cut this there is the file and similarly if we go to the blue box CDN to

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the temp directory to an LS and more grip for SH.

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Once again we also have this particular file within this particular directory.

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Now if I do an LS dash L and I grip for SH once again notice we have executable

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permissions for all groups.

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So with that now done we actually want to use the Ansible Playbook to

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effectively call those particular scripts and execute them.

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So here is what we're going to do. We'll create a new play called play two dot
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So here is what we're going to do. We'll create a new play called play two dot

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y mail and let's go into insert mode.

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We'll have our free hyphens at the top and we just call this play two testing

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the ads module.

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We're going to target the all-grut once again and we're also going to set

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gather facts to false once again.

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Now we'll define our tasks. In the first task we'll be task one.

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Test the service is running. So all I'll do is use the Ansible built-in service

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module.

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And now what I'm going to do is specify the service that I want to test and it

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's going to be the ad daemon.

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And now we'll specify the states and I want to ensure that it is started and I
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And now we'll specify the states and I want to ensure that it is started and I

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want to ensure that it is enabled.

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So if we happen to restart the server the ad service is going to automatically

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begin.

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So when we have verified that ad is indeed running an operational on our system

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we want to use that particular program.

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So we just say task two. We just say run scripts in the future.

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So what we're going to do here is use the Ansible POSIX ads module this time.

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And what I want to do is I want to specify the script file that I'm going to

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execute.

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Now where is that actually located? Well it's going to be located in the temp
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Now where is that actually located? Well it's going to be located in the temp

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directory and it's called my bash dot SH.

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This is the path for the file on both of the target devices.

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Now what I want to do here is to specify my counts.

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So in my case here let's do with account of two.

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And now I specify the unit. Well two what is it two hours two weeks two minutes

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?

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What is it? Well because as a demo we don't want to wait forever so I'll just

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say two minutes time.

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Now before I actually run this what I want to do is verify that the script has

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not actually ran yet.

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So let me go in as the Ansible user here and I'll type in the password Ansible.
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So let me go in as the Ansible user here and I'll type in the password Ansible.

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If I do a CD I'm now in the Ansible home directory.

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If I do an LS we have not actually got any particular files right here.

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However once the script has ran as per the scheduling that particular file is

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short and the home directory of the Ansible user.

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So I will just say Ansible Playbook play two dot yml and to enter.

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We'll test the service as it running. The Playbook executes if I go back to my

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yellow box.

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Inside of this home directory if I do an LS the file has not yet been created

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because the script has not executed.
WEBVTT
X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000

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However in about nine seconds time the script will have been executed and it

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will generate the file within this particular directory.

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So again now we have executed if I do an LS now the file actually has been

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generated.

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Check this out and if I go over to the blue box if I just substitute user

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become the Ansible user and just type in the password Ansible.

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If I see you to the home directory and on LS we can also see the file has also

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been generated within the home directory of the Ansible user on the blue box as

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11:58.000 --> 11:58.000
well.

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And all of this was scheduled via the @utility via Ansible.
WEBVTT
X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000

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And all of this was scheduled via the @utility via Ansible.